With recent development of widespread use of optical communications, demands are becoming strong for higher-speed transmitting and receiving circuits. Also, small low-voltage and low-power-consumption circuits are highly demanded from the point of view of cost reduction and energy saving.
In optical signal receiving circuits and optical signal receiving apparatuses, such an amplifier is generally needed that performs photoelectric conversion of the optical signal by the use of a photoelectric converter, such as a photodiode, amplifies the weak current signal output therefrom, and converts the amplified signal into an electric signal, especially differential voltage signals.
Accordingly, operability with a single low-voltage power supply has come to be demanded to such an amplifier in view of cost reduction and energy saving.
In JP09-232877A is disclosed a preamplifier for optical communication operable with a single low-voltage power supply. Especially in FIG. 1 of JP09-232877A, there is shown an example in which the source and the drain of a field-effect transistor (FET) are connected to each end of a feedback resistor of a current-voltage converting circuit employing a trans-impedance amplifier (TIA), and thus the output voltage amplitude of the current-voltage converting circuit is controlled.
In the data sheet of the product ADN2821, Analog Devices, Inc., is described a trans-impedance amplifier for optical communication. FIG. 1 in the data sheet, in particular, describes a feedback connection from the output of the differential amplifier to the input of the differential amplifier.